This invention relates to a sink strainer assembly and its method of manufacture. Reference throughout this application to "sink" is intended to include all types of sinks, basins and tubs that are conventionally connected through suitable plumbing to convey liquids to a drainage area.
Sink strainer assemblies generally include a one piece body that is attached to the sink by a locknut from the underside of the sink which makes up with matching threads formed on the strainer body. To achieve a tight seal, putty is applied under the flange of the body which hardens into a cement-like substance.
There are basically four types of strainers available.
Type One--is a one piece molded plastic body with a stainless steel flange attached to the flange or upper part of the molded strainer. This is done for appearance and to protect the most vulnerable area of the strainer from the wear and tear associated with sink use.
Type Two--is a one piece deep drawn hollow body made from heavy gauge (0.050" to 0.060") brass or stainless steel strip. The threads are cut into the body.
Type Three--is a deep drawn hollow body made from light gauge (0.025" to 0.035") stainless steel strip. This type of body utilizes a roll thread for make up to the sink and attachment to drain connection.
Type Four--is a molded plastic body with molded external threads for make up to sink and connection to drain. An internal liner of thin wall, deep drawn stainless steel is force fit into the entire inside of the strainer.
The advantages and disadvantages of the prior art sink strainer assemblies can be summarized as follows:
______________________________________ Advantages Disadvantages ______________________________________ Type 1 Low Cost Special wrench needed needed for 33/8" locknut. Plastic tends to discolor and does not hold up under wear and tear of sink use. Also standard putty deterio- rates plastic. Type 2 High Quality Special wrench needed for make up. In brass, chrome plating tends to wear ayay. Type 3 Low Cost Roll threads trap food particles and therefore unsanitary condition exists. Type 4 Low Cost Putty will attack and deteriorate plastic. Small drain opening will reduce drainage. Fit-all replacement basket will not fit the body. ______________________________________